Montenegro UK /mɒntɪˈniːɹəʊ/US /ˌmɑntəˈniɡɹoʊ/ noun1 •A country on the Balkan Peninsula in Southeastern Europe. Capital and largest city: Podgorica. Part of Yugoslavia until 2003, then part of Serbia and Montenegro until 2006.For centuries a theocracy ruled by bishops, Montenegro maintained its autonomy during the Ottoman period. — 1990 formsMontenegros